Restore an archived workspace when its agent is reopened

Reopening an archived agent previously dead-ended at "workspace not
found": the agent record was un-archived but its workspace stayed
archived and was never sent to the client.

The daemon now un-archives the owning workspace alongside the agent when
its backing directory still exists, and the app auto-fires the restore
ahead of the missing-workspace gate so the user lands back in the
workspace rather than a dead end.

Worktrees whose directory was deleted on archive are not yet restorable
(recreating them from their branch is a follow-up); the workspace record
now persists its base branch as groundwork for that.

packages/app/src/i18n/resources/zh-CN.ts

@@ -328,6 +328,8 @@ export const zhCN: TranslationResources = {
   workspace: {
     route: {
       loading: "正在加载 workspace",
+      restoring: "正在恢复 workspace",
+      restoreFailed: "无法恢复此 workspace — 目录可能已被移动或删除",
       connecting: "正在连接",
       hostOffline: "{{hostName}} 已离线",
       cannotReachHost: "无法连接 {{hostName}}",